The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
Fuel cost constitutes a significant part of the vehicle owner's daily expenses, and is even more significant when it comes to vehicle fleets. For many of today's vehicle fleets, fuel consumption due to unnecessary vehicle idling (i.e., keeping the engine running while the vehicle remains stationary for an extended period of time) represents a significant portion of the overall fleet fuel costs as well as vehicles' undesired emissions. Unnecessary idling often represents about 5% or more of the overall fuel consumption, therefore minimizing the unnecessary idling entails a big impact upon fleet cost savings and emissions' reductions.
In addition to the fuel consumption factor discussed above, excessive idling might create other problems. First, an idling engine does not operate at its peak temperature, and consequently fuel combustion is incomplete. As a result, fuel residues might condense on the cylinder walls, contaminate the oil and damage engine components. For example, such residues tend to deposit on spark plugs, thus, the more engine idling events occur, the higher is the drop in the average plug temperature and accelerated scaling aggregation on the plugs. This phenomenon might increase fuel consumption by 4 to 5 percent. Excessive idling can also cause water to condense in the vehicle's exhaust, which in turn can lead to corrosion and reduce the length of the exhaust system life.
A vehicle is considered to be idling anytime when the engine is running while the vehicle is stationary. However, not all of these idling periods are considered to be unnecessary. Short duration idling periods e.g. at traffic lights, stop signs, etc., are typically viewed as being situations in which idling is unavoidable or not significant enough from a fuel saving perspective, to target them for elimination, while longer idling periods are found typically to be unnecessary idling periods.